<div>你好 1</div>
<div>你好 2</div>
<div>你好 3</div>
<div>你好 4</div>
<script src="./my.jquery.js"></script>
<script>
    //$方法
    var div = $('div')
 console.log(div)
 div.html()
 div.css('background','red')
var divObj = document.querySelectorAll('div')
console.log(divObj)
</script>
